<s>
QED	B-Application
is	O
a	O
line-oriented	O
computer	O
text	B-Application
editor	I-Application
that	O
was	O
developed	O
by	O
Butler	O
Lampson	O
and	O
L	O
.	O
Peter	O
Deutsch	O
for	O
the	O
Berkeley	B-General_Concept
Timesharing	I-General_Concept
System	I-General_Concept
running	O
on	O
the	O
SDS	B-Device
940	I-Device
.	O
</s>
<s>
QED	B-Application
(	O
for	O
"	O
quick	O
editor	O
"	O
)	O
addressed	O
teleprinter	O
usage	O
,	O
but	O
systems	O
"	O
for	O
CRT	B-Device
displays	I-Device
 [ were ] 	O
not	O
considered	O
,	O
since	O
many	O
of	O
their	O
design	O
considerations	O
 [ were ] 	O
quite	O
different.	O
"	O
</s>
<s>
Ken	O
Thompson	O
later	O
wrote	O
a	O
version	O
for	O
CTSS	B-Operating_System
;	O
this	O
version	O
was	O
notable	O
for	O
introducing	O
regular	B-Language
expressions	I-Language
.	O
</s>
<s>
Thompson	O
rewrote	O
QED	B-Application
in	O
BCPL	B-Language
for	O
Multics	B-Application
.	O
</s>
<s>
The	O
Multics	B-Application
version	O
was	O
ported	O
to	O
the	O
GE-600	B-Device
system	O
used	O
at	O
Bell	O
Labs	O
in	O
the	O
late	O
1960s	O
under	O
GECOS	B-Application
and	O
later	O
GCOS	B-Application
after	O
Honeywell	O
took	O
over	O
GE	O
's	O
computer	O
business	O
.	O
</s>
<s>
The	O
GECOS-GCOS	O
port	O
used	O
I/O	O
routines	O
written	O
by	O
A	O
.	O
W	O
.	O
Winklehoff	O
.	O
</s>
<s>
Dennis	O
Ritchie	O
,	O
Ken	O
Thompson	O
and	O
Brian	O
Kernighan	O
wrote	O
the	O
QED	B-Application
manuals	O
used	O
at	O
Bell	O
Labs	O
.	O
</s>
<s>
Given	O
that	O
the	O
authors	O
were	O
the	O
primary	O
developers	O
of	O
the	O
Unix	B-Application
operating	I-Application
system	I-Application
,	O
it	O
is	O
natural	O
that	O
QED	B-Application
had	O
a	O
strong	O
influence	O
on	O
the	O
classic	O
UNIX	B-Application
text	B-Application
editors	I-Application
ed	B-Application
,	O
sed	B-Application
and	O
their	O
descendants	O
such	O
as	O
ex	B-Device
and	O
sam	B-Application
,	O
and	O
more	O
distantly	O
AWK	B-Application
and	O
Perl	B-Language
.	O
</s>
<s>
A	O
University	O
of	O
Toronto	O
team	O
consisting	O
of	O
Tom	O
Duff	O
,	O
Rob	O
Pike	O
,	O
Hugh	O
Redelmeier	O
,	O
and	O
David	O
Tilbrook	O
implemented	O
a	O
version	O
of	O
QED	B-Application
that	O
runs	O
on	O
UNIX	B-Application
;	O
David	O
Tilbrook	O
later	O
included	O
QED	B-Application
as	O
part	O
of	O
his	O
QEF	O
tool	O
set	O
.	O
</s>
<s>
QED	B-Application
was	O
also	O
used	O
as	O
a	O
character-oriented	O
editor	O
on	O
the	O
Norwegian-made	O
Norsk	O
Data	O
systems	O
,	O
first	O
Nord	O
TSS	O
,	O
then	O
Sintran	B-Operating_System
III	I-Operating_System
.	O
</s>
<s>
It	O
was	O
implemented	O
for	O
the	O
Nord-1	B-Device
computer	O
in	O
1971	O
by	O
Bo	O
Lewendal	O
who	O
after	O
working	O
with	O
Deutsch	O
and	O
Lampson	O
at	O
Project	O
Genie	O
and	O
at	O
the	O
Berkeley	O
Computer	O
Corporation	O
,	O
had	O
taken	O
a	O
job	O
with	O
Norsk	O
Data	O
(	O
and	O
who	O
developed	O
the	O
Nord	O
TSS	O
later	O
in	O
1971	O
)	O
.	O
</s>
